Many different antiperspirant and deodorant products are known for use in controlling underarm perspiration and malodor. These products are available in a variety of product forms such as solid sticks, soft solids or creams, roll-on liquids and aerosol or non-aerosol sprays. All of these different products, however, are similar in that they generally have a base formula that contains an antiperspirant active such as an aluminum and or zirconium salt, a suspending or thickening agent, and a suitable liquid carrier.
Antiperspirant and deodorant products typically contain only one skin active ingredient, that ingredient being the antiperspirant and deodorant active. There has been limited disclosure in the antiperspirant and deodorant art directed to the addition of other skin active agents to these products to provide the underarm area of the skin with more benefits than mere antiperspirant and deodorant benefits. These limited disclosures have recently been directed to the addition of various vitamins to the antiperspirant and deodorant products to provide the underarm area of the skin with benefits associated with such topical vitamin application. Such disclosures have included the topical application of water-soluble vitamins such as ascorbic acid and many of the water-soluble Vitamin B materials.
Formulating skin active agents into an antiperspirant and deodorant product raises a number of challenges, especially when such products contain water-soluble skin active agents. These water-soluble materials can be formulated as a dissolved active in an aqueous antiperspirant and deodorant formulation, but aqueous formulations tend to provide less antiperspirant efficacy than similar other anhydrous formulations and leave a wet residue after application that many consumers find undesirable. To avoid these problems commonly associated with aqueous antiperspirant and deodorant formulations, these same products can be formulated as anhydrous products containing the water-soluble skin active agent in the form of dispersed particulate solids. These anhydrous antiperspirant and deodorant products tend to provide better antiperspirant efficacy and application cosmetics.
It has been found that anhydrous antiperspirant and deodorant products containing solid, water-soluble, skin active materials often provide poor delivery of the water-soluble solid from an anhydrous matrix to the underarm area of the skin. It has also been found that this delivery of water-soluble solids can be improved by formulating the liquid carrier in the anhydrous product matrix such that the matrix is preferably and free or substantially free of organic liquids having a C Log P value of greater than about 7.0. It is believed that this particular selection of the anhydrous liquid carrier allows for improved dissolution of the water-soluble solid into sweat or other moisture on the skin, which then allows for more effective contact of the water-soluble material with the skin, thus improving the efficacy of the water-soluble material on the underarm area of the skin.
It has also been found, however, that the above-described formulations that specifically contain Vitamin B3 particulates as a water-soluble skin active agent can also result in a relatively high visible residue on the skin after application. The relatively high residue is believed to be contributed largely from the Vitamin B3 solids, which tend to have relatively high refractive indices. It has now been found that this relatively high visible residue can be reduced substantially by using small concentrations of glycerin in the formulation. It was also found that the glycerin helps with active dispersion during processing, thus allowing for a process with less reliance upon lengthy mechanical dispersion steps. It was also found that the glycerin not only reduces visible residue, but that it provides this particular formulation with a dry, silky feeling during and after application to the underarm.